Search

International audience; While the emergence of the Acheulean is well documented in East Africa at ~1.7 Ma, subsequent developments are less well understood and to some extent controversial. Here, we provide robust evidence regarding the time period between 1.6 Ma and 1.2 Ma, based on an interdisciplinary approach to the stratigraphic sequences exposed in the Gombore gully of Melka Kunture, in the upper Awash Valley of Ethiopia. Throughout the Pleistocene, the environment differed significantly from elsewhere in Africa because of the elevation at 2000 m asl, the cooler and rainy climate, the Afromontane vegetation, the development of endemic animal species, and the recurrent impact of volcanic activity. At Gombore IB, dated ~1.6 Ma, remains of Homo erectus/ergaster have been discovered, associated with a rich early Acheulean assemblage. The techno-typological analysis of the lithic record from Gombore Iγ (~1.4 Ma) and Gombore Iδ (~1.3 Ma), where substantial areas have been excavated, and the contrasting evidence from Gombore OAM Test Pit C (~1.2 Ma), suggest that the scarcity or lack of large flakes and large cutting tools at the two earlier sites is possibly not just the outcome of sampling bias, but rather of the adaptation of H. erectus/ergaster to the local resources, in a relatively isolated environment. The sites of Gombore gully provide new evidence on the complex pattern of human evolution and adaptation in East Africa during the Lower Pleistocene.

Melka Kunture est un complexe de sites paléolithiques qui s’étend sur une centaine de km2 dans la vallée supérieure de l’Awash (Éthiopie), entre 2000 et 2200 m d’altitude. Á partir d’il y a 2 millions d’années, il y a de nombreux sites avec productions lithiques de l’Oldowayen, de l’Acheuléen inférieur (Early Acheu lean), de l’Acheuléen moyen et de l’Acheuléen final, et enfin du Middle Stone Age initial (Early Middle Stone Age) et du Middle Stone Age, suivis par le Late Stone Age. Le climat, frais et pluvieux a permis le développement d’une riche végétation de type afromontagnard. Les restes d’hippopotames sont omniprésents et dominent en termes de biomasse, mais les Alcelaphini sont bien représentés, notamment avec les genres Connochaetes et Damaliscus. Des restes fossiles d’homininés ont été découverts en association directe avec l’Oldowayen, l’Acheuléen inférieur, l’Acheuléen moyen et le Middle Stone Age initial. Des empreintes d’animaux et d’homininé s ont également été trouvés, ces dernières dans des niveaux datés entre 1,2 et 0,7 millions d’années.

International audience; AbstractThe rise and spread of tropical grasslands was a signal event in the Cenozoic, causing many ungulates to evolve adaptations to a diet of graminoid tissues, or graminivory. In parallel, a lineage of monkeys (Theropithecus) is distinguished among primates for its large size and commitment to graminivory, a trait expressed by species throughout the Plio-Pleistocene fossil record and T. gelada, the sole surviving species today. An open question concerns the mechanics of how fossil species of Theropithecus handled graminoid tissues. They might have exhibited preference, selecting tissues within a given tuft, or they might have practiced indiscriminate bulk-feeding in a manner similar to large grazing ungulates. To differentiate between these handling behaviors, we used time- and graminivore-calibrated carbon stable isotope values to show progressive reliance on high-throughput bulk-feeding graminivory. Variation in this behavior explains a significant amount of variation in body mass through time, and we describe these covarying traits, which peaked during the Pleistocene, as evolutionary traps. To support this characterization, we report evidence of temporal increases in strontium isotope variability among North African theropiths, a result that suggests greater lifetime travel and energetic costs in response to diminishing food resources, a probable factor in the extinction of T. oswaldi, the largest monkey that ever lived.

Most Plio-Pleistocene sites in the Gregory Rift Valley that have yielded abundant fossil hominins lie on the Rift Valley floor. Here we report a new Pliocene site, Kantis, on the shoulder of the Gregory Rift Valley, which extends the geographical range of Australopithecus afarensis to the highlands of Kenya. This species, known from sites in Ethiopia, Tanzania, and possibly Kenya, is believed to be adapted to a wide spectrum of habitats, from open grassland to woodland. The Kantis fauna is generally similar to that reported from other contemporaneous A. afarensis sites on the Rift Valley floor. However, its faunal composition and stable carbon isotopic data from dental enamel suggest a stronger C4 environment than that present at those sites. Although the Gregory Rift Valley has been the focus of paleontologists' attention for many years, surveys of the Rift shoulder may provide new perspective on African Pliocene mammal and hominin evolution, ケニア・ナイロビ郊外で初めて発見されたアウストラロピテクス. 京都大学プレスりリス. 2016-03-24.

A well-preserved distal portion of a left humerus was discovered in 1976 during excavations directed by J. Chavaillon at the Gombore I site, in the Melka Kunture area (Ethiopia). The specimen, labelled Gombore IB-7594 (formally Melka Kunture 3, or MK3), was found in situ within unit 2 of level B, which is dated to >1.39 Ma and includes a rich Oldowan Paleolithic assemblage. Although MK3 has never been described in detail, it appeared in the literature several times and, from a taxonomic point of view, has been alternatively regarded as Homo , Australopithecus or Paranthropus . According to our analysis, MK3 exhibits a suite of features that fit the variability of the genus Homo and does not display any clear Australopithecus/Paranthropus affinity. Nevertheless, MK3 adds a great deal of variability to the genus Homo , at least as far as the Early Pleistocene fossil record is concerned. In particular, our quantitative approach, which combines traditional morphometric analyses and geometric morphometrics, highlights traits that are uncommon among the Plio-Pleistocene fossil record, while affinities with Mid-to-Late Pleistocene representatives of Homo are observed. In addition, the large size of MK3 suggests that this humerus belonged to an individual whose body weight approached 90 kg, far from the range of body size known for Homo representatives in the Early Pleistocene and as big as those of extant humans or even gorillas. We suggest that such peculiar features are of interest when regarded from an ecological perspective; thus, dimension and morphology of MK3 may be considered as an exaptation that became useful when early humans dispersed to high altitudes such as those of the upper Awash basin on the Ethiopian plateau, at heights above 2000 m.

We report here on further study of the Carnivora collected by the Dikika Research Project at Dikika, in the Hadar Formation south of the type locality since 2000. The Canidae and the otter Enhydriodon have been described elsewhere, so we focus here on the other Mustelidae and on the Felidae and Hyaenidae. All Hyaenidae are referred to Crocuta, but differences in size and tooth proportions suggest two species that might belong to distinct lineages. An associated set of upper and lower teeth is made the type of a new species of Lutra that must be close to the divergence of Lutra palaeindica, Lutra lutra, and Hydrictis maculicollis. Sample size is still small, but the Dikika assemblage differs from others of similar age in the abundance of hyenas relative to felids.

International audience; The whole collection of Suidae from Kanapoi is revised in the context of the systematics and evolution of Nyanzachoerus in the Pliocene of Eastern Africa. It contains only two species, Nyanzachoerus kanamensis and Notochoerus jaegeri. The size and morphology of their premolars overlap, but not those of their m3s. No transitional form between them is known in Kenya, but some populations from Uganda and Ethiopia display intermediate characters, suggesting that No. jaegeri could be descended from a kanamensis-like ancestor. However, the cranial remains of No. jaegeri from Kanapoi are insufficient to formally establish the affinities of the species. On the basis of the dentition, Notochoerus euilus could be descended from No. jaegeri. The noticeable absence of Kolpochoerus at Kanapoi (and in the whole Turkana Basin at that time) remains unexplained. The presence of a species with affinity to Nyanzachoerus tulotos at Ekora raises the possibility that uppermost Miocene sediments occur there.

International audience; We describe here several specimens of the genus Theropithecus from the southern shore of Lake Assal in the Republic of Djibouti; they are the first record of the genus from this country. We assign them to a derived stage of T. oswaldi. This identification has implications for the age of the informal ‘Formation 1’ from this area, which should probably be assigned to the Middle Pleistocene. In addition, the presence of T. oswaldi close to the Bab el Mandeb Strait strongly suggests that the species followed this route to India, rather than a more northern one.

Dating to more than four million years ago (Ma), the Mursi Formation is among the oldest of the Plio-Pleistocene Omo Group deposits in the lower Omo Valley of southwestern Ethiopia. The sedimentary sequence is exposed along a strip ∼35 km by 4 km, but it has received relatively little attention due to the difficult access to this area. Although expeditions to the lower Omo Valley between 1968 and 1973 focused primarily on the Usno and Shungura Formations, survey of the Mursi Formation produced a faunal collection of about 250 specimens deriving exclusively from the Yellow Sands area at the southern extent of the exposures. In 2009, we reinitiated an investigation of the formation by focusing on the most northern exposures, and a new fossil site, Cholo, was identified. Cholo is depositionally similar to the lowermost exposures at the Yellow Sands, although no stratigraphic correlation between the two localities has yet been made. The fossiliferous sediments at Cholo are capped by a prominent vitric tuff that is compositionally distinct from any other known tephra preserved in East African rift basins, including the only known vitric tuff at the Yellow Sands. The faunal assemblage of the Yellow Sands area presents interesting characteristics: the fossils generally show little weathering and include a large proportion of suids (44% of the mammalian fauna) and a small proportion of bovids (14%) compared with other Pliocene African sites. The sample is also unusual in the high frequency of deinotheres (7%). Taxon-specific stable carbon isotopic composition of the Mursi mammals tends to show generally higher proportions of C3 diets compared with other Pliocene sites in East Africa and Chad. This and the particular faunal proportions suggest that the environments represented by the Mursi Formation were more closed than those of other Pliocene sites.

It is generally believed that the skull CCEC-161821 of Acinonyx pardinensis from Saint-Vallier, an Early Pleistocene French locality, is similar to that of the modern cheetah, in contrast to several other Late Pliocene and Early Pleistocene Old World felids with cheetah-like teeth, assigned either to Acinonyx Brookes, 1828, or to Sivapanthera Kretzoi, 1929. Morphological comparisons and morphometric analysis of the fossil and recent material show that the Acinonyx pardinensis from Saint-Vallier, although dentally similar to the modern cheetah, is not cheetah-like in its skull shape. All those Late Pliocene and Early Pleistocene forms can also be included in Acinonyx, implying that the characteristic skull shape of the modern form is probably a recent acquisition.

Carbon and oxygen isotopes of mammalian tooth enamel were used to reconstruct paleoenvironments of Australopithecus afarensis from the middle Pliocene locality of Dikika, Ethiopia. Isotopic analyses were conducted on 210 mammalian herbivore teeth from 15 different taxa collected from the Basal Member (~3.8-3.42 Ma) and Sidi Hakoma Member (3.42-3.24 Ma) of the Hadar Formation. The isotopic analyses aim specifically at reconstructing shifts in the relative abundance of C(4) grasses in mammalian diets, and more generally at paleoclimate factors such as aridity and seasonality, as well as habitat structure. Carbon isotopic data suggest a wide range of foraging strategies, characterized by mixed C(3)/C(4) to C(4)-dominated diets in wooded grasslands to open woodlands. Weighted average C(4) dietary proportions range between 60% and 86% in the Basal Member and 49% and 74% in the Sidi Hakoma Member. Paleoclimatic conditions based on the reconstructed mean annual water deficit from the δ(18)O(enamel) values indicate a wetter climate as compared to either the early Pliocene or the Pleistocene nearby. The middle Pliocene habitat structure at Dikika could be as diverse as open grassland and wooded grassland, and woodland to forest in the Sidi Hakoma Member while wooded grassland, woodland to grassland are evident in the Basal Member. All habitats except closed woodland and forest are persistent through both members; however, the relative proportion of individual habitats changed through time. These changes could have put the fauna in competition for preferred habitats and food resources, which could have forced migration, adaptation to other resources and/or extinction. Thus, the existence of A. afarensis throughout the middle Pliocene indicates either this species might have adapted to a wide range of habitats, or its preferred habitat was not affected by the observed environmental changes.

http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=17198722&dopt=Citation; International audience; We describe here a new species of Dolichopithecus, D. balcanicus n. sp., from the Pliocene (late Ruscinian) of the Balkans. Although known by mandibular remains only, it is readily distinguished from the common European species, D. ruscinensis, by its smaller size, much shallower mandibular corpus, and crowding of the premolars. Ukrainian finds of "Adelopithecus" can be accommodated into D. ruscinensis, as a separate, smaller subspecies, D. ruscinensis hypsilophus, but the specimens reported from Asia are more distant, and they probably represent a separate subgenus of Dolichopithecus, the valid name of which is D. (Parapresbytis) Kalmykov & Mashchenko.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6R-4K8SC9K-3&_user=10&_coverDate=11%2F14%2F2006&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=941fa6219b71220a7d0fde44d04bc2f9; International audience; A multi proxy approach was performed to characterize vegetation in southwestern Bulgaria during the end of the Early and the Middle Turolian (8.7–7.0 Ma). This period was marked by eustatic fluctuations in the Mediterranean Sea that are well documented. In order to estimate the impact of these marine events on continental landscapes, dental microwear and stable isotope profiles in enamel were used to characterize feeding habits of extinct bovids, and in turn vegetation. Analyses were made on permanent molars of fossil bovids from two Late Miocene localities: Hadjidimovo-1 (Early/Middle Turolian) and Kalimantsi (Middle Turolian). Carbon isotopes profiles of Tragoportax rugosifrons and Miotragocerus gaudryi from the Hadjidimovo-1 indicate a pure C3-based diet for the two boselaphini. Large inter-individual differences in absolute δ18O values were found for M. gaudryi suggesting little reliance on drinking water due to a browsing diet. Dental microwear shows that none of the bovid species exclusively grazed. In Hadjidimovo-1, microwear evidence suggests mixed feeding habits for Tragoportax rugosifrons, Gazella sp., and Palaeoreas lindermayeri and a leaf browsing diet for Miotragocerus gaudryi. Palaeoreas lindermayeri from Hadjidimovo-1 has a bimodal pattern indicating that its feeding preferences were tied to seasonal food availabilities. At Kalimantsi, Miotragocerus gaudryi show variations between individuals whereas Tragoportax cf. amalthea was an exclusive browser. Palaeoreas lindermayeri and Gazella sp. were also mixed feeders in Kalimantsi. Our combined approach shows no evidence for dense forested environments during the Early and Middle Turolian, and then supports previous hypotheses based on faunal analyses. Our results rather suggest that southwestern Bulgaria was dominated by open wooded landscapes where C3 graminoids grew in abundance among the herbaceous layer. Finally, microwear data suggest that the proportion of dicotyledons such as forbs, bushes or shrubs was probably higher in the plant communities of Kalimantsi than in those of Hadjidimovo-1.

In this paper we report for the first time hominin remains from the Basal Member of the Hadar Formation at Dikika, in the Awash Valley of Ethiopia, dating to greater than 3.4 Ma. The new fossil, DIK-2-1, is a fragment of a left mandible and associated dentition. The mandible is attributed to Australopithecus afarensis. However, the new fossil exhibits some metric and morphological features that have not previously been seen in the A. afarensis hypodigm, increasing the already impressive degree of variation in the mandibular sample of the species. 2005 Elsevier Ltd. All rights reserved.

International audience; The Asbole area in the Lower Awash Valley yielded a diverse fauna of large and small mammals, associated with an Acheulean industry. The most notable forms are a potentially new species of herpestid, a large collection of Kolpochoerus majus, and the earliest known Bos in Africa. Biochronologically, this fauna belongs to the earliest Middle Pleistocene, and is roughly contemporaneous with the Bodo site further south. Paleoenvironmentally, the fauna suggests a mosaic of landscapes among which humid environments, grasslands and forests, are predominant.

To obtain a pdf version for private use only, please contact the authors.; International audience; In a series of papers, Sahnouni et al. (1996, 2002) and Sahnouni and de Heinzelin (1998) have reported the results of their renewed excavations atthe important Algerian localities of Ain Hanech and Ain Boucherit, first studied by Arambourg (e.g., Arambourg, 1970, 1979). According to the latest paper by Sahnouni and co-workers (Sahnouni et al., 2002), Ain Hanech would belong to the Olduvai subchron, dated to 1.77–1.95 Ma. This would make it by far the earliest North African site with evidence of hominid presence, and the time-equivalent of Olduvai Bed I, circum- KBS tuff levels at Koobi Fora, and Omo Shungura Member H. However, a review of the evidence put forward by Sahnouni et al. (2002) casts doubt on their conclusions. This evidence consists of 1) paleomagnetism, 2) biochronology, and 3) archaeology. They are discussed in this order below, preceded by a review of the more continuous Moroccan Atlantic sequence.; Discussion de l'appartenance au subchron Olduvai pour le gisement de l'Ain Hanech proposée par Sahnouni et al. sur la base des éléments connus pour la longue séquence continue du Plio-pléistocène du Maroc atlantique (région de Rabat-Casablanca principalement).

We report on a diverse fauna from the Busidima-Telalak region of the Afar in Ethiopia. The fossiliferous sediments are characterized by river bank deposits. During our first field season thirty one mammalian species were encountered. Fossils are nicely preserved and abundant. Bovids, carnivores, monkeys, and large rodents are the most common taxa. The fauna points to a Middle Pleistocene age (0.2 to 0.8 Ma). Our preliminary paleoenvironmental reconstruction indicates that our fossil assemblage is derived from a rather wet and closed environment. This condition is unique as sites of this time period were reported to be more open and dry.

The biogeographic relationships of North African Miocene-Pliocene rodent faunas are assessed using two different methods, factor analysis and parsimony analysis of endemicity. The Mediterranean basin is a true biogeographic province. Within it, North Africa makes up a sub-province of its own, only slightly closer to the Ibero-Occitanian sub-province than to the eastern Mediterranean one. These three sub-provinces retain their permanency over time, localities within them being clustered according to their geological age rather than by geographic location. The Miocene-Pliocene is a period of strong, but transitory similarity between the north and south, while there is a steady trend toward homogenisation of the northern Mediterranean. Most of the exchanges occur, through France, between the eastern Mediterranean and eastern Spain, and between the latter area and the rest of Iberia and North Africa, while there are very few trans-Mediterranean and southern longitudinal exchanges.

The new site of Lissasfa near Casablanca (Morocco) has yielded a rich rodent fauna, which includes: 050 a new species of Paraethomys close to the Spanish ones; a Mus which could be the earliest in North-Africa; a new species of Ruscinomys, with little reduced third molars; a rare Myocricetodon similar to late Miocene Spanish forms; a new species of Protatera, also reminding of the Spanish Mio-Pliocene forms, but with a quite peculiar M1; a second gerbillid species, rare, which compares favourably with a poorly known form from the early Pliocene of Tunisia; Irhoudia sp.; Atlantoxerus sp.; and the rare Lophiomys. This association is rather different from other faunas of similar age in North Africa, and this is a drawback against precise dating, but Lissasfa is most unlikely to be younger than the early Pliocene, thus demonstrating that the “Quaternary” sequence in Casablanca is much longer than previously believed.

In Northern Chad, the site of Kolle in the Djourab erg has yielded a vertebrate fauna including 21 species, 14 of which are Mammals. This fauna provides evidence of a mosaic of environments: fresh-water, woodlands, grasslands. In spite of possible taphonomic or collecting bias, and of some endemicity, this fauna allows us to propose an age in the range 5-4 My.

Three Pleistocene vertebrate localities in lacustrine deposits which accumulated in interdune depressions were discovered in the south-western part of the An Nafud sand sea (northern Saudi Arabia). Although the fossil vertebrate fauna is restricted in diversity, its composition and stage of evolution suggest an Early Pleistocene age in contrast with the recent Pleistocene or Holocene lake beds occurring in several other interdune depressions in central and southern An Nafud. The Nafud fauna has clear African affinities whereas faunas from the Levant, dating from the Middle Pleistocene onwards, contain typically European elements.

Resume La grande faune associee aux derniers Neandertaliens de Zafarraya est assez originale. Le bouquetin y domine largement les autres herbivores, parmi lesquels on remarque E. hydruntinus, rare en Espagne, et le chamois, jamais signale a une latitude aussi meridionale. Chez les carnivores, dont le plus commun est la panthere, on note l'absence de l'ours des cavernes et surtout du loup, remplace par le dhole. L'assemblage de bouquetins comprend des individus des deux sexes et de tous âges. L'analyse de la distribution spatiale des elements anatomiques du bouquetin et des carnivores montre que le role de l'Homme dans la constitution des assemblages est le plus marque vers — 32 000 BP, avec une intervention accrue des carnivores vers — 30 000 BP. La grotte a pu etre utilisee comme camp de chasse provisoire.

Resume Le gisement de Ahl al Oughlam a livre la premiere faune importante de carnivores d'Afrique du Nord, et l'une des plus riches d'Afrique. Elle comprend 23 taxons dont 13 nouveaux, appartenant â la plupart des familles de carnivores, les mieux representees etant les felides (6 especes), les hyenides et les mustelides (4 especes chacune). Plusieurs genres n'avaient pas encore ete decouverts en Afrique du Nord, comme Pliocrocuta, Chasmaporthetes, Nyctereutes, Prepoecilogale , alors que le morse ( Alachtherium ) est signale pour la premiere fois en Afrique; de nombreux autres genres etaient encore inconnus dans la region avant le milieu ou meme la fin du Pleistocene, comme Herpestes, Viverra, Genetta, Acinonyx, Ursus, Poecilictis, Mellivora, Lutra . La faune de carnivores de Ahl al Oughlam, ecologiquement tres diversifiee, se distingue au moins autant de celles d'Eurasie que de celles d'Afrique orientale et meridionale; les nombreuses similitudes avec les unes et les autres permettent neanmoins de confirmer l'âge de 2,5 Ma qui avait ete propose pour le gisement.

Resume Les Rongeurs du Pliocene final de Ahl al Oughlam, connus par plusieurs milliers de dents, ne comprennentpourtant que 6 especes. Hystrix et le Ctenodactylide Irhoudia sont tres rares; les Murides Paraethomys, Praomys et Mus sont un peu plus primitifs qu'a Irhoud Ocre. Une espece nouvelle de Gerbillus ressemble beaucoup a G. campestris, malgre son âge ancien. Les Insectivores sont presque tous des Soricides; le plus abondant est un “Episoriculus” semblable a celui d'Irhoud Ocre; une nouvelle espece de Suncus est le premier fossile de ce genre en Afrique du Nord; Erinaceus (Atelerix) n'est represente que par 2 dents. La microfaune est moins diversifiee que dans les gisements plus recents, ou la predominance des Gerbillides temoigne d'un milieu plus ouvert et plus sec, et Ahl al Oughlam semble anterieur a la degradation climatique de la fin du Pliocene.

Resume Tous les Suides du Pliocene superieur de Ahl al Oughlam (Casablanca, Maroc) sont rapportes a Kolpochoerusphacochoeroides Thomas , 1884 . Cette espece se distingue bien de “K.” afarensis comme de K. limnetes d'Afrique Orientale par le raccourcissement du museau, la forte taille des canines, meme chez les femelles, la reduction des premolaires anterieures et une P4/ avec une fovea postero-linguale. Elle appartient au groupe herbivore qui inclut aussi K. limnetes, K. paiceae d'Afrique du Sud et l'hylochere, a l'interieur duquel K. limnetes, est-africain, s'est individualise le premier. Sous reserve d'une vitesse d'evolution des M3 uniforme, l'âge de Ahl al Oughlam peut etre evalue 2,4 ma, âge parfaitement compatible avec les indications tirees du reste de la faune.

The late Miocene of Macedonia has yielded several rich faunal assemblages, ranging from late Vallesian to late Turolian. They may be compared to the classical localities of Pikermi, Samos and Maragheh. Taxonomic comparisons based upon updated faunal lists allowed us to compute faunal similarity indices, which were submitted to principal component and cluster analysis. On the graphs, “Ravin de la Pluie” is always remote from the other Macedonian fossil mammal localities: it can only be explained by its Vallesian age. The other Macedonian sites cluster next, demonstrating some provinciality of this area during the Turolian. Comparisons of the frequencies of the various taxonomic groups support the installation of a more forested environment in the latest faunal set, Dytiko. The indices of diversity and the rank-abundance curves seem also to reflect a change of the ecological conditions during the Turolian: the fauna of “Ravin de la Pluie” and of the Vathylakkos-Prochoma-“Ravin des Zouaves” group is marked by the predominance of 1 or 2 species, while the species frequency of the Dytiko set is more balanced, suggesting warmer climate and less contrasted climatic conditions. Another way of evaluating the ecological significance of the fossil assemblages is the analysis of the distribution of the body weight of each category of mammals in each fauna. When possible we used the cenogram method or a multivariate analysis of the number of species in each weight class (excluding small mammals, which are very rare in Macedonia); we have analysed in this way 25 fossil and 23 recent localities. We show that, although all the fossil localities are separated from the recent ones, it is possible to deduce an open environment in “Ravin de la Pluie” and a more forested one in Dytiko.

Resume La partie inferieure de la Formation Segui en Tunisie centralea livre pour la premiere fois une collection de Vertebres fossiles d'âge miocene superieur. La liste faunique comprend de nombreux poissons, plusieurs Reptiles, un Sirenien, un grand Tetralophodon, Hipparion (deux especes ?), un Rhinocerotine, des Bovides, un Giraffide, un Anthracothere et peutetre Nyanzachoerus. A cote de ces taxons connus dans d'autres localites d'Afrique du Nord, on trouve aussi quelques Mammiferes mentionnes ou decrits pour la premiere fois au Maghreb: Choerolophodon, Brachypotherium, un Suide qui semble voisin de Propotamochoerus des Siwaliks, et un nouveau genre de Bovide qui est peut-etre le plus ancien Hippotragini connu. La faune est un peu plus recente que celles de la Formation Beglia du Bled Douarah. La datation de ces sites du Djebel Krechem m'a conduit a reviser la biostratigraphie des principaux gisements a grands Mammiferes d'Afrique du Nord, avec les resultats principaux suivants: a) les faunes du Bled Douarah appartiennent a la base du Miocene superieur, et Hipparion pourrait y apparaitre vers ll m.a. b) la faune de Sahabi date du Miocene terminal, et non du Pliocene, a l'exception, sans doute, de quelques specimens collectes jadis par les Italiens.

Resume Le gisement de la carriere Thomas III (Casablanca, Maroc) a livre, avec une faune du Pleistocene moyen (Tensiftien),une mandibule de lynx, Lynx thomasi n. sp., dont la dentition est caracterisee par des premolaires hautes et complexs et une carnassiere tres longue. Cette nouvelle espece derive peut-etre de lynx post-villafranchiens europeens.

Resume Une analyse cladistique, basee sur des caracteres crâniens (specialement la nature des «cornes), dentaires et squelettiques, permet de definir la famille des Giraffidae, et de reconsiderer les subdivisions classiquement admises. Canthumeryx est le Giraffidae le plus ancien et le plus primitif. Les Sivatheriini, Giraffokeryx et les Giraffini constituent une trichotomie non resolue. Dans cette derniere tribu, Okapia est le genre-frere de Giraffa .

Resume Les faunes de grands Mammiferes d'Afrique du Nord presentent encore de nombreuses similitudes avec celles d'Eurasie au Miocene terminal., mais le remplissage post-Messinien de la Mediterranee privilegie au Plio-Pleistocene les migrations intraafricaines. Des elements eurasiatiques remplacent ensuite progressivement les especes ethiopiennes du Maghreb, qui ne s'isole cependant de l'Afrique orientale que vers la fin du Pleistocene superieur, avec l'etablissement d'une barriere saharienne continue.